CN114982536A

CN114982536A - Preparation method of breathable water-drop-free mulching film based on temperature-adjustable air exchange layer

Info

Publication number: CN114982536A
Application number: CN202210519817.4A
Authority: CN
Inventors: 李文卓
Original assignee: Nanjing Forestry University
Current assignee: Nanjing Forestry University
Priority date: 2021-02-02
Filing date: 2021-02-02
Publication date: 2022-09-02
Anticipated expiration: 2041-02-02
Also published as: CN114982536B; CN114793722A; CN112806199A; CN114793722B; CN112806199B

Abstract

The invention provides a breathable waterless mulching film based on a temperature-adjustable air exchange layer, which is characterized in that a surface film layer, a temperature-adjustable air exchange layer and a hydrophilic layer are sequentially arranged on the mulching film from top to bottom, the surface film layer is distributed with air exchange holes, the temperature-adjustable air exchange layer is composed of a butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative thermal material, and the negative thermal material is ZrW loaded with benzoyl peroxide ₂ O ₈ The hydrophilic layer is composed of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer. The prepared mulching film has the advantages of improvingThe carbon dioxide concentration and the ammonia concentration in the mulching film covering space are reduced, meanwhile, no obvious water drops are formed on the inner surface of the mulching film, and the high soil temperature can be maintained.

Description

Preparation method of breathable water-drop-free mulching film based on temperature-adjustable air exchange layer

The technical field is as follows:

the invention belongs to the technical field of agricultural mulching films, and particularly relates to a preparation method of a breathable water-drop-free mulching film based on a temperature-adjustable air exchange layer.

Background art:

soil drought caused by low temperature and little rain is a main factor for limiting the agricultural development in northern areas of China, and aiming at the limiting factors, the northern areas of China are generally dealt with by applying an agricultural mulching film technology. At present, the mulching film covered on the surface of the agricultural soil is proved to have multiple functions of improving the ground temperature, preserving water, fertilizer, weed, disease and insect prevention, inhibiting salt, protecting seedlings, improving the ground photo-thermal conditions and the like. The traditional plastic film that uses at present is mostly the plastics plastic film of hydrophobic nature macromolecular material, lays monoblock plastics plastic film on soil surface during the use, has accomplished the plastic film and has laid the operation promptly. The operation mode of the mulching film is simple and convenient, but the traditional plastic mulching films are airtight, so that a closed environment is formed in the space covered by the traditional plastic mulching films, and the gas in the space covered by the traditional mulching films cannot be exchanged with the fresh air outside. However, the growth and development of the crops are respiratory, i.e. the photosynthesis of the crops is to inhale CO in the environment ₂ Introduction of CO ₂ The nutrient components required by the growth of the crops are converted, but when the crops are in the closed space, the air can not be exchanged in time, so that the CO in the closed environment is generated ₂ The gas concentration will decrease continuously when the CO is in the closed environment ₂ When the concentration is lower than 300ppm, the photosynthesis of crops can be inhibited, and the problems of slow growth, flower and fruit dropping, yield reduction and the like of vegetables are caused. In addition, fertilizers such as urea are also frequently used in agricultural soil to promote crop growth, but the urea fertilizers are chemically changed in soil and release harmful gases such as ammonia gas, and if the harmful gases such as ammonia gas cannot be timely discharged in a closed space covered by a mulching film, the ammonia gas can be continuously accumulated to a high concentration, so that vegetable plants are easily killed. In actual agricultural production, peasants can be ventilative for crops through pricking some holes on traditional plastic film, but these holes of pricking out are physical hole, and these physical hole can remain on the plastic film after producing always, can not automatic closure, and this has just caused that external cold air can enter into in the plastic film mulching space from these physical holes to make the plastic film lose the heat preservation effect.

In addition, the traditional mulching film is generally made of hydrophobic polymer materials, so that water drops (or water drops) are easy to form on the inner surface facing soil when the traditional mulching film is used, namely the traditional mulching film does not have the performance of preventing the water drops. The drop of agricultural plastic film is great to the agricultural production harm, and this kind of drop of water has reduced the permeability of sunshine to the plastic film on the one hand to consequently can reduce the soil temperature of plastic film mulching, moreover because the drop of water on the plastic film is the sphere more, and the focus sunshine is converged to spherical drop of water, and then can lead to burning seedling phenomenon, causes the harm to agricultural production.

The invention content is as follows:

in order to solve the problems in the prior art, the invention provides a breathable water-drop-free mulching film and a preparation method thereof.

The utility model provides a ventilative waterless drop plastic film, its characterized in that, the plastic film sets gradually facial mask layer (1) from top to bottom, but temperature regulation's layer of taking a breath (2) and hydrophilic layer (3), the facial mask layer distribute bleeder vent (11), but temperature regulation's layer of taking a breath by compound negative heat material of butyl acrylate-styrene-chlorosulfonated polyethylene copolymer constitute, negative heat material (21) are ZrW of load benzoyl peroxide ₂ O ₈ The butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material comprises the following components in parts by weight: 20-35 parts of butyl acrylate, 2-7 parts of styrene, 1.5-6.5 parts of chlorosulfonated polyethylene and 3-8 parts of negative heat material, wherein the hydrophilic layer is composed of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer, and the hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer comprises the following components in parts by weight: 15-30 parts of hydroxypropyl acrylate, 1-5 parts of styrene, 1-5 parts of chlorosulfonated polyethylene and 20-40 parts of polyvinyl alcohol; the preparation method of the breathable water-drop-free mulching film comprises the following steps:

(1) dissolving 1 part by weight of benzoyl peroxide in 99 parts by weight of toluene solvent to obtain solution A, and then dissolving 30 parts by weight of ZrW with particle size of 100-32 meshes ₂ O ₈ Soaking in the A solution at 25 deg.C for 15 hr, and soaking in ZrW ₂ O ₈ Taking out, and air-drying at room temperature for 10h to obtain the ZrW loaded with benzoyl peroxide ₂ O ₈ Negative heatMaterial wherein benzoyl peroxide comprises ZrW loaded with benzoyl peroxide by weight ₂ O ₈ 0.1-0.12% of the total weight of the negative thermal material;

(2) dissolving 1.5-6.5 parts by weight of chlorosulfonated polyethylene in 2-7 parts by weight of styrene in a container to obtain a solution B; dissolving 0.5 part by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain a solution C; then adding 2.3 parts by weight of sodium dodecyl sulfate, 3.1 parts by weight of OP-10 emulsifier and 20 parts by weight of deionized water into the solution B, and stirring for 30min at room temperature between the rotation speed of 350-;

(3) heating the container containing emulsion D to 82 ℃ in a water bath, and then obtaining the benzoyl peroxide-loaded ZrW from the product obtained in step (1) ₂ O ₈ Taking out 3-8 parts by weight of the negative heat material particles, adding the negative heat material particles into the emulsion D, and dripping 20-35 parts by weight of butyl acrylate into the emulsion D under stirring, wherein the dripping speed is 1 drop per 2 seconds, and the stirring speed is 250 r/min; dropwise adding the solution C obtained in the step (2) into the emulsion D while dropwise adding butyl acrylate, wherein the dropping speed is 1 drop per 5 seconds;

(4) after the butyl acrylate and the solution C are dropwise added in the step (3), heating the reaction system to 85 ℃, and stirring at the constant temperature for 5 hours at the constant temperature for reaction, wherein the stirring speed is 250 r/min; after the constant-temperature stirring reaction is finished, cooling the obtained mixed solution to room temperature, and adding concentrated ammonia water to adjust the pH of the mixed solution to be neutral to obtain white emulsion E;

(5) coating the white emulsion E obtained in the step (4) on the surface of the facial mask layer, controlling the thickness of the emulsion E layer to be 0.1-0.3mm, and drying at room temperature to obtain a transparent temperature-adjustable ventilation layer which is attached to the surface of the facial mask layer and consists of a butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material;

(6) dissolving 1-5 parts by weight of chlorosulfonated polyethylene in 1-5 parts by weight of styrene to obtain a solution F; dissolving 0.5 part by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain solution G;

(7) then adding 20-40 parts by weight of polyvinyl alcohol powder, 3.3 parts by weight of sodium dodecyl sulfate, 5.1 parts by weight of OP-10 emulsifier and 50 parts by weight of deionized water into the solution F obtained in the step (6), and stirring at room temperature of 360r/min at the rotating speed of 350-;

(8) heating a container containing the emulsion H obtained in the step (7) in water bath to 82 ℃, and then adding 15-30 parts by weight of hydroxypropyl acrylate into the emulsion H under stirring at the temperature, wherein the dropping speed is 1 drop per 2 seconds, and the stirring speed is 250 r/min; dropwise adding the solution G obtained in the step (6) into the emulsion H at the dropping speed of 1 drop per 5 seconds while dropwise adding hydroxypropyl acrylate; after the hydroxypropyl acrylate and the solution G are dripped, heating the reaction system to 85 ℃, and stirring and reacting for 5 hours at constant temperature at the temperature, wherein the stirring speed is 250 r/min; after the constant-temperature stirring reaction is finished, cooling the obtained mixed solution to room temperature, and adding concentrated ammonia water to adjust the pH of the mixed solution to be neutral to obtain white emulsion I;

(9) and (3) coating the white emulsion I obtained in the step (8) on the surface of the ventilation layer which is obtained in the step (5) and can be adjusted in temperature, controlling the thickness of the emulsion I layer to be 0.08-0.2mm, and drying at room temperature to obtain a hydrophilic layer which is attached to the surface of the ventilation layer and consists of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer.

The breathable water-drop-free mulching film can be obtained through the steps (1) to (9).

Wherein the material of the mask layer is polyethylene or polyvinyl chloride, the pore size of the mask layer distributed with air holes is 0.5-3mm, and the distribution density of the air holes is 5-20/m ² 。

The invention is different from the prior art in that the invention achieves the following technical effects:

the test results of the effect embodiment show that the mulching film prepared by the invention has the effects of improving the concentration of carbon dioxide gas and reducing the concentration of ammonia gas in a mulching film covering space, and meanwhile, no obvious water drops are formed on the inner surface of the mulching film facing the soil, so that higher soil temperature can be maintained. This is because of the following factors:

1. the temperature-adjustable ventilation layer consists of a butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative thermal material, wherein the negative thermal material is ZrW loaded with benzoyl peroxide ₂ O ₈ The negative thermal material is a material which can contract when heated and expand when cooled, and ZrW ₂ O ₈ The material is a negative thermal expansion material with excellent performance, and has negative thermal expansion performance within the temperature range of 0.3-1050.0K, namely, the material can trigger negative thermal expansion behavior at normal temperature and even lower temperature. Thus, this ZrW is present at high daytime temperatures ₂ O ₈ The volume of the negative heat material is correspondingly contracted, so that the negative heat material particles are separated from a polymer matrix of the butyl acrylate-styrene-chlorosulfonated polyethylene copolymer to a certain extent, pores are formed on the air exchange layer, air with higher temperature in the daytime can be exchanged to the space covered by the mulching film through the pores, carbon dioxide in the outside air is supplemented to the space covered by the mulching film, and meanwhile ammonia in the space covered by the mulching film is exchanged to the space outside the mulching film. At night, no sunlight irradiates, the temperature of the environment drops, the volume of the negative heat material particles can expand along with the drop of the temperature of the environment, and then the pores between the negative heat material particles and the polymer matrix become smaller (or closed), so that cold air at night is difficult to exchange into a space covered by the mulching film, the temperature of the covered soil is maintained by the mulching film, and the effect of protecting crops covered by the mulching film from being damaged by the cold air at night is also achieved.

2. The negative thermal material in the temperature-adjustable air exchange layer is ZrW loaded with benzoyl peroxide ₂ O ₈ Benzoyl peroxide can initiate free radical polymerization of organic monomer with double bond, so that benzoyl peroxide-loaded ZrW ₂ O ₈ The polymerization of butyl acrylate and styrene monomers in the system can be initiated on the surface of the negative thermal material particles to form a layer of dense polymer shell with certain strength to wrap the surface of the negative thermal material particles, which is beneficial to forming temperature-controllable pores in the ventilation layer (for this reason, further explanation is made in the analysis of the working principle of the mulching film of the invention later).

3. The butyl acrylate-styrene-chlorosulfonated polyethylene copolymer contains butyl acrylate and styrene, so that the copolymer has good film-forming property, the chlorosulfonated polyethylene has the property of improving flexibility of formed film, and can be well dissolved in styrene, when the styrene monomer is copolymerized, the styrene can make the chlorosulfonated polyethylene and other components in the copolymer have better compatibility, and make the chlorosulfonated polyethylene molecular chain and other high-molecular chains in the copolymer mutually interweave together at molecular level so as to form the copolymer whose distribution of all components is more uniform.

4. The hydrophilic layer is composed of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer, the structure of a hydroxypropyl acrylate monomer in the copolymer is similar to the molecular structure of a butyl acrylate monomer in the ventilation layer, and the hydroxypropyl acrylate monomer has a hydrophilic hydroxyl group besides double bonds and ester bonds. The hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer composition also includes a strongly hydrophilic polyvinyl alcohol component, and the two components of hydroxypropyl acrylate and polyvinyl alcohol in the hydrophilic layer can give excellent hydrophilicity to the hydrophilic layer, so that the contact angle of water drop on the surface of said hydrophilic layer is small (not greater than 10 deg.), and the condensed water drops can be quickly spread on the surface of said hydrophilic layer and can be flowed away. Because no (or less) water drops are formed on the surface of the hydrophilic layer of the mulching film, sunlight easily penetrates through the mulching film and directly irradiates the surface of soil covered by the mulching film, and the absorption of the water drops to solar energy is reduced, so that the breathable water-drop-free mulching film is beneficial to efficiently utilizing solar energy and maintaining the higher temperature of the soil covered by the mulching film.

5. The hydrophilic layer and the temperature-adjustable ventilation layer are similar in components, and both the hydrophilic layer and the temperature-adjustable ventilation layer contain styrene, chlorosulfonated polyethylene, butyl acrylate and hydroxypropyl acrylate with similar structures, so that the hydrophilic layer and the ventilation layer have good compatibility with each other, namely the hydrophilic layer can be well attached to the surface of the temperature-adjustable ventilation layer, the problem of layer-to-layer separation caused by incompatibility of the two layers and the occurrence of a water channeling phenomenon between the layers can be avoided. In addition, the copolymers in the hydrophilic layer and the temperature-adjustable air exchange layer are transparent and colorless, so that sunlight can easily penetrate through the films of the invention, the soil covered by the mulching film can easily receive the radiation of the sunlight, and the temperature of the soil covered by the mulching film can be improved.

6. The surface film layer is distributed with air holes, and the external fresh air can enter the lower temperature-adjustable ventilation layer through the air holes and enter the space covered by the mulching film through the air holes.

Document 1(ZL2018101375050) reports an anticorrosive hydrophilic coating containing chlorinated natural rubber, which forms a coating structure comprising an upper hydrophilic surface layer containing polyvinyl alcohol resin and a lower anticorrosive layer containing chlorinated natural rubber, wherein the surface of the coating also has the effect of spreading out water drops to prevent water drops from forming, but the coating does not have a temperature-adjustable air exchange effect.

Document 2(CN1485359A) reports an agricultural non-dropping film, which is prepared by blending a non-dropping agent into low density polyethylene, then feeding the material into a twin-screw extruder, melt-extruding, water-cooling, drying, granulating, and blowing the material into a film by a film blowing machine. The mulching film can only achieve the effect of no water drop, but the coating does not have the ventilation effect of temperature adjustment.

Document 3(CN 104335850 a) also reports a double-layered mulching film with good air permeability, which has an upper layer and a lower layer, and has air holes arranged in the upper layer and the lower layer in a staggered manner, so that the air permeability is excellent, but the air permeability of the mulching film still cannot change along with the temperature.

Different from documents 1 to 3, the mulching film provided by the invention comprises a temperature-adjustable ventilation layer and a hydrophilic layer, wherein the two layers are mutually compatible due to similar components and are adhered together, and the temperature-adjustable ventilation layer can automatically adjust the ventilation property of the mulching film along with the change of the environmental temperature, so that the CO in a mulching film covering space is improved ₂ The concentration of gas reduces NH in the mulching film covering space ₃ The concentration of (c); the hydrophilic layer on the inner surface of the mulching film can prevent the inner surface of the mulching film from easily forming water drops, so that sunlight can easily penetrate through the mulching film, and the temperature of soil can be favorably increased.

Document 4 (patent No. 2020202046049) proposes a breathable and heat-absorbing liquid rubber-based mulching film, which comprises a polyvinyl film on both the upper and lower surfaces, a liquid rubber complex humic acid air-drying heat-absorbing film sandwiched between the polyvinyl films, and spherical negative heat materials embedded in the liquid rubber complex humic acid air-drying heat-absorbing film. Document 4 discloses that the pore size of the surface of the mulching film can be changed with the change of the environmental temperature, and accordingly, the pore size also has the function of automatically adjusting the air permeability of the mulching film with the environmental temperature. However, the upper and lower surfaces of the mulching film proposed in document 4 are both made of hydrophobic polyethylene polymers, so that the mulching film does not have the performance of preventing water drops, and the mulching film of document 4 is black and opaque, so that sunlight cannot easily penetrate through the mulching film of document 4, and water drops bonded by the mulching film made of hydrophobic materials can absorb solar energy when evaporating, so that the space covered by the mulching film of document 4 is slow in temperature rise speed, and the ground temperature is not high. The mulching film is transparent, the inner surface of the mulching film facing soil is hydrophilic, and water drops are not easy to form, so that sunlight easily passes through the mulching film, and no water drops absorb solar energy, so that the temperature rising speed of a mulching space of the mulching film is high, and the ground temperature is higher.

The working principle analysis of the breathable water-drop-free mulching film prepared by the invention is as follows:

in the preparation step (1) of the invention, ZrW is added ₂ O ₈ The particles are put in toluene solution containing benzoyl peroxide, and benzoyl peroxide molecules in the solution can be adsorbed on ZrW ₂ O ₈ On the surface of the particles, thereby forming benzoyl peroxide-loaded ZrW ₂ O ₈ Wherein the adsorbed benzoyl peroxide can comprise benzoyl peroxide-loaded ZrW ₂ O ₈ 0.1-0.12% of the total weight of the negative thermal material; with ZrW not loaded with benzoyl peroxide ₂ O ₈ In contrast, benzoyl peroxide-loaded ZrW ₂ O ₈ The negative heat material particles can initiate butyl acrylate and styrene monomer molecules to generate polymerization reaction on the surfaces of the negative heat material particles, so that a polymer shell formed on the surfaces of the negative heat material particles is of a compact structure instead of a soft structure, the polymer shell of the compact structure has good rigidity and small deformability, when the ambient temperature rises in daytime, the negative heat material shrinks, and the compact polymer shell wrapping the negative heat material particles has good rigidity and is not easy to deform, and cannot shrink along with the shrinkage of the negative heat material, so that the negative heat material particles can be polymerized on the surfaces of the negative heat material particles and compact particlesA gap is formed between the polymer shells, so that an exchange channel of indoor and outdoor gas is opened. When the ambient temperature at night is reduced, the negative heat material particles expand towards the surrounding polymer shell, so that a gap between the negative heat material and the polymer shell is closed, an exchange channel of indoor and outdoor air is also closed, and cold air cannot enter a space covered by the mulching film at night.

The steps (2) to (4) in the preparation steps are reaction steps for preparing the composite negative heat material emulsion containing the butyl acrylate-styrene-chlorosulfonated polyethylene copolymer, in the emulsion preparation step, the chlorosulfonated polyethylene is firstly dissolved in the styrene, and because the chlorosulfonated polyethylene has good solubility in the styrene, the chlorosulfonated polyethylene can not easily form granules or blocks in the emulsion, but can form a macromolecular copolymer with uniformly distributed components by cross interpenetration of the molecular form and other macromolecular chains. In addition, in the steps (2) to (4), the ammonium persulfate initiator can initiate the polymerization reaction of butyl acrylate and styrene monomer molecules with double bonds in the solution; sodium dodecyl sulfate and OP-10 (a chemical raw material, alkylphenol polyoxyethylene ether obtained by condensation reaction of alkylphenol and ethylene oxide, which is a type in an OP series of emulsifiers) play a role of an emulsifier, and can suspend small oil-in-water particles of a copolymer generated after polymerization reaction in a solution to form an emulsion.

The preparation step (5) is to coat the composite negative heat material emulsion containing the butyl acrylate-styrene-chlorosulfonated polyethylene copolymer on a polyethylene or polyvinyl chloride mask layer, wherein the chlorosulfonated polyethylene has good adhesion to the polyethylene or the polyvinyl chloride, so that the butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material emulsion is easily attached to the mask layer, after the moisture in the emulsion is evaporated, a solid coating containing the butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material can be formed on the mask layer, and the solid coating can generate the function of opening and closing a ventilation channel along with the temperature change.

The preparation steps (6) - (8) are reaction steps for preparing the emulsion containing hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer, and the reaction principle is similar to that for preparing the emulsion containing butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative thermal material.

The preparation step (9) is to coat the emulsion containing hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer on the ventilation layer which can be adjusted in temperature and is obtained in the step (5), because the emulsion containing hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer contains the same styrene and chlorosulfonated polyethylene components as those in the ventilation layer and the chlorosulfonated polyethylene has good cohesiveness, the emulsion containing hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer is easy to attach to the surface of the ventilation layer, after the water in the emulsion is evaporated, a solid coating containing hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer is formed on the ventilation layer, the solid coating has good hydrophilicity, and water drops on the surface of the solid coating can spread and flow away quickly, so that the hydrophilic surface of the breathable water-drop-free mulching film has the property of not forming water drops.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention.

Fig. 1 is a perspective view of a breathable water-drop-free mulching film of the present invention.

FIG. 2 is a cross-sectional view of a breathable, water-drop-free mulch film of the present invention.

Reference numbers in the figures: 1-a mask layer; 2-temperature adjustable ventilation layer; 3-a hydrophilic layer; 11-air holes; 21-negative thermal material.

Detailed Description

The above and further features and advantages of the present invention are described in more detail in the following examples. The chemical raw materials used in the following examples are all commercially available, chemically pure reagents;

ZrW ₂ O ₈ powder, 99.5% pure, was purchased from Shanghai Diangyang industries, Inc., and sieved to select different mesh sizes of granules for use in the following examples.

Chlorosulfonated polyethylene (model: CSM3304, manufactured by Jilin petrochemical Co., Ltd.) was purchased from Shanghai, short-range International trade Co., Ltd.

Polyvinyl alcohol (type: 1788) was purchased from Shanghai minister and promoter Chemicals and technology Co., Ltd.

Example 1

Referring to the attached drawings, the permeable waterless mulching film is characterized in that a polyethylene surface film layer (1), a temperature-adjustable ventilation layer (2) and a hydrophilic layer (3) are sequentially arranged from top to bottom, air holes (11) are distributed in the polyethylene surface film layer, the aperture of each air hole is 3mm, and the distribution density of the air holes in the surface film layer is 20/m ² The temperature-adjustable ventilation layer is composed of a butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative thermal material, and the negative thermal material (21) is ZrW loaded with benzoyl peroxide ₂ O ₈ The butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material comprises the following components in parts by weight: 20 parts of butyl acrylate, 2 parts of styrene, 1.5 parts of chlorosulfonated polyethylene and 8 parts of negative heat material, wherein the hydrophilic layer is composed of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer, and the hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer comprises the following components in parts by weight: 30 parts of hydroxypropyl acrylate, 5 parts of styrene, 5 parts of chlorosulfonated polyethylene and 40 parts of polyvinyl alcohol; the preparation method of the breathable water-drop-free mulching film comprises the following steps:

(1) dissolving 1 part by weight of benzoyl peroxide in 99 parts by weight of toluene solvent to obtain solution A, and then dissolving 30 parts by weight of ZrW with particle size of 100-80 meshes ₂ O ₈ Soaking in the A solution at 25 deg.C for 15 hr, and soaking in ZrW ₂ O ₈ Taking out, and air-drying at room temperature for 10h to obtain the ZrW loaded with benzoyl peroxide ₂ O ₈ Negative thermal material, wherein the weight of benzoyl peroxide is ZrW loaded with benzoyl peroxide ₂ O ₈ 0.1% of the total weight of the negative thermal material;

(2) dissolving 1.5 parts by weight of chlorosulfonated polyethylene in 2 parts by weight of styrene in a container to obtain a solution B; dissolving 0.5 part by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain a solution C; then adding 2.3 parts by weight of sodium dodecyl sulfate, 3.1 parts by weight of OP-10 emulsifier and 20 parts by weight of deionized water into the solution B, and stirring at the rotating speed of 350r/min at room temperature for 30min to obtain emulsion D;

(3) heating the container containing emulsion D to 82 ℃ in a water bath, and then obtaining the benzoyl peroxide-loaded ZrW from the product obtained in step (1) ₂ O ₈ Taking out 8 parts by weight of the negative heat material particles, adding the negative heat material particles into the emulsion D, and dropwise adding 20 parts by weight of butyl acrylate into the emulsion D under stirring, wherein the dropping speed is 1 drop per 2 seconds, and the stirring speed is 250 r/min; dropwise adding the solution C obtained in the step (2) into the emulsion D at the dropping speed of 1 drop per 5 seconds while dropwise adding butyl acrylate;

(5) coating the white emulsion E obtained in the step (4) on the surface of the facial mask layer, controlling the thickness of the emulsion E layer to be 0.1mm, and drying at room temperature to obtain a transparent temperature-adjustable ventilation layer which is attached to the surface of the facial mask layer and consists of a butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material;

(6) dissolving 5 parts by weight of chlorosulfonated polyethylene in 5 parts by weight of styrene to obtain a solution F; dissolving 0.5 part by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain solution G;

(7) then adding 40 parts by weight of polyvinyl alcohol powder, 3.3 parts by weight of sodium dodecyl sulfate, 5.1 parts by weight of OP-10 emulsifier and 50 parts by weight of deionized water into the solution F obtained in the step (6), and stirring at the room temperature of 360r/min for 300min to obtain emulsion H;

(8) heating the container containing the emulsion H obtained in the step (7) to 82 ℃ in a water bath, and then adding 30 parts by weight of hydroxypropyl acrylate into the emulsion H under stirring at the temperature, wherein the dropping speed is 1 drop per 2 seconds, and the stirring speed is 250 r/min; dripping the solution G obtained in the step (6) into the emulsion H at the dripping speed of 1 drop per 5 seconds while dripping hydroxypropyl acrylate; after the hydroxypropyl acrylate and the solution G are dripped, heating the reaction system to 85 ℃, and stirring and reacting for 5 hours at constant temperature at the temperature, wherein the stirring speed is 250 r/min; after the constant-temperature stirring reaction is finished, cooling the obtained mixed solution to room temperature, and adding concentrated ammonia water to adjust the pH of the mixed solution to be neutral to obtain white emulsion I;

(9) and (3) coating the white emulsion I obtained in the step (8) on the surface of the ventilation layer which is obtained in the step (5) and can be adjusted in temperature, controlling the thickness of the emulsion I layer to be 0.08mm, and drying at room temperature to obtain a hydrophilic layer which is attached to the surface of the ventilation layer and consists of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer.

A breathable water-drop-free mulch film of example 1 was obtained via steps (1) - (9).

Example 2

Referring to the attached drawing, the mulching film is sequentially provided with a polyvinyl chloride (PVC) mask layer (1), a temperature-adjustable ventilation layer (2) and a hydrophilic layer (3) from top to bottom, the PVC mask layer is distributed with air holes (11), the aperture of each air hole is 2.3mm, and the distribution density of the air holes in the mask layer is 17/m ² The temperature-adjustable ventilation layer is composed of a butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative thermal material, and the negative thermal material (21) is ZrW loaded with benzoyl peroxide ₂ O ₈ The butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material comprises the following components in parts by weight: 24 parts of butyl acrylate, 3 parts of styrene, 2.5 parts of chlorosulfonated polyethylene and 6 parts of negative heat material, wherein the hydrophilic layer is composed of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer, and the hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer comprises the following components in parts by weight: 27 parts of hydroxypropyl acrylate, 4 parts of styrene, 4 parts of chlorosulfonated polyethylene and 35 parts of polyvinyl alcohol; the preparation method of the breathable water-drop-free mulching film comprises the following steps:

(1) dissolving 1 weight part of benzoyl peroxide in 99 weight parts of nailObtaining solution A in benzene solvent, and then adding 30 parts by weight of ZrW with the particle size of 80-65 meshes ₂ O ₈ Soaking in the A solution at 25 deg.C for 15h, and soaking ZrW ₂ O ₈ Taking out, and air-drying at room temperature for 10h to obtain the ZrW loaded with benzoyl peroxide ₂ O ₈ Negative thermal material, wherein the weight of benzoyl peroxide is ZrW loaded with benzoyl peroxide ₂ O ₈ 0.11 percent of the total weight of the negative heat material;

(2) dissolving 2.5 parts by weight of chlorosulfonated polyethylene in 3 parts by weight of styrene in a container to obtain a solution B; dissolving 0.5 part by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain a solution C; then adding 2.3 parts by weight of sodium dodecyl sulfate, 3.1 parts by weight of OP-10 emulsifier and 20 parts by weight of deionized water into the solution B, and stirring at the room temperature of 355r/min for 30min to obtain emulsion D;

(3) heating the container containing emulsion D to 82 ℃ in a water bath, and then obtaining the benzoyl peroxide-loaded ZrW from the product obtained in step (1) ₂ O ₈ Taking out 6 parts by weight of the negative heat material particles, adding the negative heat material particles into the emulsion D, and dropwise adding 24 parts by weight of butyl acrylate into the emulsion D under stirring, wherein the dropping speed is 1 drop per 2 seconds, and the stirring speed is 250 r/min; dropwise adding the solution C obtained in the step (2) into the emulsion D at the dropping speed of 1 drop per 5 seconds while dropwise adding butyl acrylate;

(4) after the butyl acrylate and the solution C are dropwise added in the step (3), heating the reaction system to 85 ℃, and stirring at the constant temperature for 5 hours at the temperature, wherein the stirring speed is 250 r/min; after the constant-temperature stirring reaction is finished, cooling the obtained mixed solution to room temperature, and adding concentrated ammonia water to adjust the pH of the mixed solution to be neutral to obtain white emulsion E;

(6) dissolving 4 parts by weight of chlorosulfonated polyethylene in 4 parts by weight of styrene to obtain a solution F; dissolving 0.5 part by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain solution G;

(7) then adding 35 parts by weight of polyvinyl alcohol powder, 3.3 parts by weight of sodium dodecyl sulfate, 5.1 parts by weight of OP-10 emulsifier and 50 parts by weight of deionized water into the solution F obtained in the step (6), and stirring at the rotating speed of 355r/min at room temperature for 300min to obtain emulsion H;

(8) heating a container containing the emulsion H obtained in the step (7) in a water bath to 82 ℃, and then adding 27 parts by weight of hydroxypropyl acrylate into the emulsion H under stirring at the temperature, wherein the dropping speed is 1 drop per 2 seconds, and the stirring speed is 250 r/min; dripping the solution G obtained in the step (6) into the emulsion H at the dripping speed of 1 drop per 5 seconds while dripping hydroxypropyl acrylate; after the hydroxypropyl acrylate and the solution G are dripped, heating the reaction system to 85 ℃, and stirring and reacting for 5 hours at constant temperature at the temperature, wherein the stirring speed is 250 r/min; after the constant-temperature stirring reaction is finished, cooling the obtained mixed solution to room temperature, and adding concentrated ammonia water to adjust the pH of the mixed solution to be neutral to obtain white emulsion I;

(9) and (3) coating the white emulsion I obtained in the step (8) on the surface of the ventilation layer which is obtained in the step (5) and can be adjusted in temperature, controlling the thickness of the emulsion I layer to be 0.12mm, and drying at room temperature to obtain a hydrophilic layer which is attached to the surface of the ventilation layer and consists of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer.

A breathable, water-drop-free mulch film of example 2 was obtained via steps (1) - (9).

Example 3

Referring to the attached drawings, the permeable waterless mulching film is characterized in that a polyethylene surface film layer (1), a temperature-adjustable ventilation layer (2) and a hydrophilic layer (3) are sequentially arranged from top to bottom, air holes (11) are distributed in the polyethylene surface film layer, the aperture of each air hole is 1.7mm, and the distribution density of the air holes in the surface film layer is 13/m ² The temperature-adjustable ventilation layer is composed of a butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative thermal material, and the negative thermal material (21) is ZrW loaded with benzoyl peroxide ₂ O ₈ Said butyl acrylate-phenethyl esterThe alkene-chlorosulfonated polyethylene copolymer composite negative heat material comprises the following components in parts by weight: 28 parts of butyl acrylate, 4 parts of styrene, 3.5 parts of chlorosulfonated polyethylene and 5 parts of negative heat material, wherein the hydrophilic layer is composed of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer, and the hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer comprises the following components in parts by weight: 23 parts of hydroxypropyl acrylate, 3 parts of styrene, 3 parts of chlorosulfonated polyethylene and 30 parts of polyvinyl alcohol;

the preparation method of the breathable water-drop-free mulching film comprises the following steps:

(1) dissolving 1 part by weight of benzoyl peroxide in 99 parts by weight of toluene solvent to obtain solution A, and then dissolving 30 parts by weight of ZrW with particle size of 65-60 meshes ₂ O ₈ Soaking in the A solution at 25 deg.C for 15h, and soaking ZrW ₂ O ₈ Taking out, and air-drying at room temperature for 10h to obtain the ZrW loaded with benzoyl peroxide ₂ O ₈ Negative thermal material, wherein the weight of benzoyl peroxide is ZrW loaded with benzoyl peroxide ₂ O ₈ 0.1% of the total weight of the negative thermal material;

(2) dissolving 3.5 parts by weight of chlorosulfonated polyethylene in 4 parts by weight of styrene in a container to obtain a solution B; dissolving 0.5 part by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain a solution C; then adding 2.3 parts by weight of sodium dodecyl sulfate, 3.1 parts by weight of OP-10 emulsifier and 20 parts by weight of deionized water into the solution B, and stirring at the rotating speed of 360r/min at room temperature for 30min to obtain emulsion D;

(3) heating the container containing emulsion D to 82 ℃ in a water bath, and then obtaining the benzoyl peroxide-loaded ZrW from step (1) ₂ O ₈ Taking out 5 parts by weight of the negative heat material particles, adding the negative heat material particles into the emulsion D, and dropwise adding 28 parts by weight of butyl acrylate into the emulsion D under stirring, wherein the dropping speed is 1 drop per 2 seconds, and the stirring speed is 250 r/min; dropwise adding the solution C obtained in the step (2) into the emulsion D at the dropping speed of 1 drop per 5 seconds while dropwise adding butyl acrylate;

(5) coating the white emulsion E obtained in the step (4) on the surface of the facial mask layer, controlling the thickness of the emulsion E layer to be 0.15mm, and drying at room temperature to obtain a transparent temperature-adjustable ventilation layer which is attached to the surface of the facial mask layer and consists of a butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material;

(6) dissolving 3 parts by weight of chlorosulfonated polyethylene in 3 parts by weight of styrene to obtain a solution F; dissolving 0.5 part by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain solution G;

(7) then adding 30 parts by weight of polyvinyl alcohol powder, 3.3 parts by weight of sodium dodecyl sulfate, 5.1 parts by weight of OP-10 emulsifier and 50 parts by weight of deionized water into the solution F obtained in the step (6), and stirring at the rotating speed of 350r/min at room temperature for 300min to obtain emulsion H;

(8) heating a container containing the emulsion H obtained in the step (7) in water bath to 82 ℃, and then adding 23 parts by weight of hydroxypropyl acrylate into the emulsion H under stirring at the temperature, wherein the dropping speed is 1 drop per 2 seconds, and the stirring speed is 250 r/min; dripping the solution G obtained in the step (6) into the emulsion H at the dripping speed of 1 drop per 5 seconds while dripping hydroxypropyl acrylate; after the hydroxypropyl acrylate and the solution G are dripped, heating the reaction system to 85 ℃, and stirring and reacting for 5 hours at constant temperature at the temperature, wherein the stirring speed is 250 r/min; after the constant-temperature stirring reaction is finished, cooling the obtained mixed solution to room temperature, and adding concentrated ammonia water to adjust the pH of the mixed solution to be neutral to obtain white emulsion I;

(9) and (3) coating the white emulsion I obtained in the step (8) on the surface of the ventilation layer which is obtained in the step (5) and can be adjusted in temperature, controlling the thickness of the emulsion I layer to be 0.1mm, and drying at room temperature to obtain a hydrophilic layer which is attached to the surface of the ventilation layer and consists of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer.

A breathable water-drop-free mulch film of example 3 was obtained via steps (1) - (9).

Example 4

Referring to the attached drawings, the permeable waterless mulching film is characterized in that a polyethylene surface film layer (1), a temperature-adjustable ventilation layer (2) and a hydrophilic layer (3) are sequentially arranged from top to bottom, air holes (11) are distributed in the polyethylene surface film layer, the aperture of each air hole is 1.1mm, and the distribution density of the air holes in the surface film layer is 9/m ² The temperature-adjustable ventilation layer is composed of a butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative thermal material, and the negative thermal material (21) is ZrW loaded with benzoyl peroxide ₂ O ₈ The butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material comprises the following components in parts by weight: the heat-insulating material comprises 32 parts of butyl acrylate, 6 parts of styrene, 5 parts of chlorosulfonated polyethylene and 4 parts of a negative heat material, wherein the hydrophilic layer is composed of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer, and the hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer comprises the following components in parts by weight: 19 parts of hydroxypropyl acrylate, 2 parts of styrene, 2 parts of chlorosulfonated polyethylene and 25 parts of polyvinyl alcohol;

(1) dissolving 1 part by weight of benzoyl peroxide in 99 parts by weight of toluene solvent to obtain solution A, and then mixing 30 parts by weight of ZrW with a particle size of 60-48 meshes ₂ O ₈ Soaking in the A solution at 25 deg.C for 15h, and soaking ZrW ₂ O ₈ Taking out, and air-drying at room temperature for 10h to obtain the ZrW loaded with benzoyl peroxide ₂ O ₈ Negative thermal material, wherein the weight of benzoyl peroxide is ZrW loaded with benzoyl peroxide ₂ O ₈ 0.12% of the total weight of the negative thermal material;

(2) dissolving 5 parts by weight of chlorosulfonated polyethylene in 6 parts by weight of styrene in a container to obtain a solution B; dissolving 0.5 part by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain a solution C; then adding 2.3 parts by weight of sodium dodecyl sulfate, 3.1 parts by weight of OP-10 emulsifier and 20 parts by weight of deionized water into the solution B, and stirring at the rotating speed of 355r/min at room temperature for 30min to obtain emulsion D;

(3) heating the container containing the emulsion D in a water bath to 82 ℃, and then obtaining the benzoyl peroxide-loaded ZrW from the step (1) ₂ O ₈ Taking out 4 parts by weight of the negative heat material particles, adding the negative heat material particles into the emulsion D, and dropwise adding 32 parts by weight of butyl acrylate into the emulsion D under stirring, wherein the dropping speed is 1 drop per 2 seconds, and the stirring speed is 250 r/min; dropwise adding the solution C obtained in the step (2) into the emulsion D at the dropping speed of 1 drop per 5 seconds while dropwise adding butyl acrylate;

(5) coating the white emulsion E obtained in the step (4) on the surface of the facial mask layer, controlling the thickness of the emulsion E layer to be 0.2mm, and drying at room temperature to obtain a transparent temperature-adjustable ventilation layer which is attached to the surface of the facial mask layer and consists of a butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material;

(6) dissolving 2 parts by weight of chlorosulfonated polyethylene in 2 parts by weight of styrene to obtain a solution F; dissolving 0.5 part by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain solution G;

(7) then adding 25 parts by weight of polyvinyl alcohol powder, 3.3 parts by weight of sodium dodecyl sulfate, 5.1 parts by weight of OP-10 emulsifier and 50 parts by weight of deionized water into the solution F obtained in the step (6), and stirring at the rotating speed of 355r/min at room temperature for 300min to obtain emulsion H;

(8) heating the container containing the emulsion H obtained in the step (7) to 82 ℃ in a water bath, and then adding 19 parts by weight of hydroxypropyl acrylate into the emulsion H under stirring at the temperature, wherein the dropping speed is 1 drop per 2 seconds, and the stirring speed is 250 r/min; dripping the solution G obtained in the step (6) into the emulsion H at the dripping speed of 1 drop per 5 seconds while dripping hydroxypropyl acrylate; after the hydroxypropyl acrylate and the solution G are dripped, heating the reaction system to 85 ℃, and stirring and reacting for 5 hours at constant temperature at the temperature, wherein the stirring speed is 250 r/min; after the constant-temperature stirring reaction is finished, cooling the obtained mixed solution to room temperature, and adding concentrated ammonia water to adjust the pH of the mixed solution to be neutral to obtain white emulsion I;

A breathable water-drop-free mulch film of example 4 was obtained via steps (1) - (9).

Example 5

Referring to the attached drawings, the breathable water-drop-free mulching film is characterized in that a polyvinyl chloride (PVC) surface film layer (1), a temperature-adjustable ventilation layer (2) and a hydrophilic layer (3) are sequentially arranged from top to bottom, air holes (11) are distributed in the PVC surface film layer, the aperture of each air hole is 0.5mm, and the distribution density of the air holes in the surface film layer is 5/m ² The temperature-adjustable ventilation layer is composed of a butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative thermal material, and the negative thermal material (21) is ZrW loaded with benzoyl peroxide ₂ O ₈ The butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material comprises the following components in parts by weight: 35 parts of butyl acrylate, 7 parts of styrene, 6.5 parts of chlorosulfonated polyethylene and 3 parts of negative heat material, wherein the hydrophilic layer is composed of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer, and the hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer comprises the following components in parts by weight: 15 parts of hydroxypropyl acrylate, 1 part of styrene, 1 part of chlorosulfonated polyethylene and 20 parts of polyvinyl alcohol;

(1) dissolving 1 part by weight of benzoyl peroxide in 99 parts by weight of toluene solvent to obtain solution A, and then dissolving 30 parts by weight of ZrW with particle size of 48-32 meshes ₂ O ₈ Soaking at 25 deg.CSoaking in the solution A for 15h, and soaking the ZrW ₂ O ₈ Taking out, and air-drying at room temperature for 10h to obtain the ZrW loaded with benzoyl peroxide ₂ O ₈ Negative thermal material, wherein the weight of benzoyl peroxide is ZrW loaded with benzoyl peroxide ₂ O ₈ 0.12% of the total weight of the negative thermal material;

(2) dissolving 6.5 parts by weight of chlorosulfonated polyethylene in 7 parts by weight of styrene in a container to obtain a solution B; dissolving 0.5 part by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain a solution C; then adding 2.3 parts by weight of sodium dodecyl sulfate, 3.1 parts by weight of OP-10 emulsifier and 20 parts by weight of deionized water into the solution B, and stirring at the rotating speed of 350r/min at room temperature for 30min to obtain emulsion D;

(3) heating the container containing emulsion D to 82 ℃ in a water bath, and then obtaining the benzoyl peroxide-loaded ZrW from the product obtained in step (1) ₂ O ₈ Taking out 3 parts by weight of the negative heat material particles, adding the negative heat material particles into the emulsion D, and dripping 35 parts by weight of butyl acrylate into the emulsion D under stirring, wherein the dripping speed is 1 drop per 2 seconds, and the stirring speed is 250 r/min; dropwise adding the solution C obtained in the step (2) into the emulsion D at the dropping speed of 1 drop per 5 seconds while dropwise adding butyl acrylate;

(5) coating the white emulsion E obtained in the step (4) on the surface of the facial mask layer, controlling the thickness of the emulsion E layer to be 0.3mm, and drying at room temperature to obtain a transparent temperature-adjustable ventilation layer which is attached to the surface of the facial mask layer and consists of a butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material;

(6) dissolving 1 part by weight of chlorosulfonated polyethylene in 1 part by weight of styrene to obtain a solution F; dissolving 0.5 part by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain solution G;

(7) then adding 20 parts by weight of polyvinyl alcohol powder, 3.3 parts by weight of sodium dodecyl sulfate, 5.1 parts by weight of OP-10 emulsifier and 50 parts by weight of deionized water into the solution F obtained in the step (6), and stirring at room temperature for 300min at the rotating speed of 360r/min to obtain emulsion H;

(8) heating a container containing the emulsion H obtained in the step (7) in water bath to 82 ℃, and then adding 15 parts by weight of hydroxypropyl acrylate into the emulsion H under stirring at the temperature, wherein the dropping speed is 1 drop per 2 seconds, and the stirring speed is 250 r/min; dropwise adding the solution G obtained in the step (6) into the emulsion H at the dropping speed of 1 drop per 5 seconds while dropwise adding hydroxypropyl acrylate; after the hydroxypropyl acrylate and the solution G are dripped, heating the reaction system to 85 ℃, and stirring and reacting for 5 hours at constant temperature at the temperature, wherein the stirring speed is 250 r/min; after the constant-temperature stirring reaction is finished, cooling the obtained mixed solution to room temperature, and adding concentrated ammonia water to adjust the pH of the mixed solution to be neutral to obtain white emulsion I;

(9) and (3) coating the white emulsion I obtained in the step (8) on the surface of the ventilation layer which is obtained in the step (5) and can be adjusted in temperature, controlling the thickness of the emulsion I layer to be 0.2mm, and drying at room temperature to obtain a hydrophilic layer which is attached to the surface of the ventilation layer and consists of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer.

A breathable, water-drop-free mulch film of example 5 was obtained via steps (1) - (9).

Comparative example 6

The present example is to prepare a mulching film according to the steps described in example 4, and the present example is different from example 4 in that the temperature-adjustable ventilation layer does not have a negative heat material, and other components related to the structure of the mulching film, the material of the surface film layer, the pore size and density of the ventilation holes, the composition of the components, the content of the components, and the like are the same as those of example 4. The preparation steps of this example are as follows:

(1) dissolving 5 parts by weight of chlorosulfonated polyethylene in 6 parts by weight of styrene in a container to obtain a solution B; dissolving 0.5 part by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain a solution C; then adding 2.3 parts by weight of sodium dodecyl sulfate, 3.1 parts by weight of OP-10 emulsifier and 20 parts by weight of deionized water into the solution B, and stirring at the room temperature of 355r/min for 30min to obtain emulsion D;

(2) heating the container containing the emulsion D in a water bath to 82 ℃, dropwise adding 32 parts by weight of butyl acrylate into the emulsion D under stirring, wherein the dropping speed is 1 drop per 2 seconds, and the stirring speed is 250 r/min; dropwise adding the solution C obtained in the step (1) into the emulsion D at the dropping speed of 1 drop per 5 seconds while dropwise adding butyl acrylate;

the remaining preparation steps were the same as the preparation steps (4) to (9) of example 4.

Comparative example 7

This example is a mulching film prepared according to the method described in example 4, and the difference between this example and example 4 is that the negative thermal material in the temperature-adjustable ventilation layer is ZrW ₂ O ₈ Instead of ZrW loaded with benzoyl peroxide ₂ O ₈ Other materials related to the structure of the mulching film, the material of the surface film layer, the pore diameter and density of the air holes, the component composition, the component content and the like are the same as those in the embodiment 4. The preparation steps of this example are as follows:

(1) dissolving 5 parts by weight of chlorosulfonated polyethylene in 6 parts by weight of styrene in a container to obtain a solution B; dissolving 0.5 part by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain a solution C; then adding 2.3 parts by weight of sodium dodecyl sulfate, 3.1 parts by weight of OP-10 emulsifier and 20 parts by weight of deionized water into the solution B, and stirring at the rotating speed of 355r/min at room temperature for 30min to obtain emulsion D;

(2) heating the container containing the emulsion D in water bath to 82 ℃, and then adding 4 parts by weight of ZrW with the size of 60-48 meshes ₂ O ₈ Adding the particles into the emulsion D obtained in the step (2), and dripping 32 parts by weight of butyl acrylate into the emulsion D under stirring, wherein the dripping speed is 1 drop per 2 seconds, and the stirring speed is 250 r/min; dropwise adding the solution C obtained in the step (1) into the emulsion D at the dropping speed of 1 drop per 5 seconds while dropwise adding butyl acrylate;

Comparative example 8

This example is a mulching film prepared according to example 4, and the difference between this example and example 4 is that the particle size of the negative heat material in the temperature-adjustable ventilation layer is 9-28 mesh, the amount is outside the range of the claims, and other elements related to the structure of the mulching film, the material of the surface film layer, the pore size and density of the ventilation holes, the composition of the components, the content of the components, and the like are the same as those in example 4. The preparation steps of this example are as follows:

(1) dissolving 1 part by weight of benzoyl peroxide in 99 parts by weight of toluene solvent to obtain solution A, and then dissolving 30 parts by weight of ZrW with particle size of 9-28 meshes ₂ O ₈ Soaking in the A solution at 25 deg.C for 15h, and soaking ZrW ₂ O ₈ Taking out, and air-drying at room temperature for 10h to obtain the ZrW loaded with benzoyl peroxide ₂ O ₈ Negative thermal material, wherein the weight of benzoyl peroxide is ZrW loaded with benzoyl peroxide ₂ O ₈ 0.12% of the total weight of the negative heat material;

the remaining preparation steps were the same as the preparation steps (2) to (9) of example 4.

Comparative example 9

The present embodiment is to prepare the mulching film according to the description of embodiment 4, and the difference between this embodiment and embodiment 4 is that the particle size of the negative heat material in the temperature-adjustable ventilation layer is 115-400 mesh, the amount is outside the scope of the claims, and other elements related to the structure of the mulching film, the material of the surface film layer, the aperture and density of the ventilation hole, the composition and the content of the components are the same as those in embodiment 4. The preparation steps of this example are as follows:

(1) 1 part by weight of benzoyl peroxide is dissolved in 99 parts by weight of toluene solvent to obtain solution A, and then 30 parts by weight of ZrW with the particle size of 115-400 meshes ₂ O ₈ Soaking in the A solution at 25 deg.C for 15h, and soaking ZrW ₂ O ₈ Taking out, and air-drying at room temperature for 10h to obtain the ZrW loaded with benzoyl peroxide ₂ O ₈ Negative thermal material, wherein the weight of benzoyl peroxide is ZrW loaded with benzoyl peroxide ₂ O ₈ 0.12% of the total weight of the negative thermal material;

the remaining preparation steps were the same as those (2) to (9) in example 4.

Comparative example 10

This example is a mulching film prepared according to example 4, and the difference between this example and example 4 is that the amount of hydroxypropyl acrylate in the ventilation layer is 10 parts by weight, and the amount of polyvinyl alcohol is 15 parts by weight, both of which are outside the range of claims, and the other components related to the structure of the mulching film, the material of the surface film layer, the pore size and density of the ventilation holes, the composition of the components, the content of the components, etc. are the same as those in example 4. The preparation steps of this example are as follows:

the preparation steps (1) to (6) of this example were the same as the steps (1) to (6) of example 4.

(7) Then adding 15 parts by weight of polyvinyl alcohol powder, 3.3 parts by weight of sodium dodecyl sulfate, 5.1 parts by weight of OP-10 emulsifier and 50 parts by weight of deionized water into the solution F obtained in the step (6), and stirring at the rotating speed of 355r/min at room temperature for 300min to obtain emulsion H;

(8) heating a container containing the emulsion H obtained in the step (7) in water bath to 82 ℃, and then adding 10 parts by weight of hydroxypropyl acrylate into the emulsion H under stirring at the temperature, wherein the dropping speed is 1 drop per 2 seconds, and the stirring speed is 250 r/min; dropwise adding the solution G obtained in the step (6) into the emulsion H at the dropping speed of 1 drop per 5 seconds while dropwise adding hydroxypropyl acrylate; after the hydroxypropyl acrylate and the solution G are dripped, heating the reaction system to 85 ℃, and stirring and reacting for 5 hours at constant temperature at the temperature, wherein the stirring speed is 250 r/min; after the constant-temperature stirring reaction is finished, cooling the obtained mixed solution to room temperature, and adding concentrated ammonia water to adjust the pH of the mixed solution to be neutral to obtain white emulsion I;

this example was the same as example 4 in preparation step (9).

Comparative example 11

The present example was conducted in accordance with the method described in example 4, and the present example was different from example 4 in that no chlorosulfonated polyethylene was present in the air-permeable layer and the hydrophilic layer, and the other components related to the structure of the mulching film, the material of the surface film layer, the pore size and density of the air-permeable holes, the composition of the components, and the content of the components were the same as those in example 4. The preparation steps of this example are as follows:

this example was conducted in the same manner as in example 4, except that the production step (1) was conducted.

(2) Adding 6 parts by weight of styrene into a container to obtain a solution B; dissolving 0.5 part by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain a solution C; then adding 2.3 parts by weight of sodium dodecyl sulfate, 3.1 parts by weight of OP-10 emulsifier and 20 parts by weight of deionized water into the solution B, and stirring at the room temperature of 355r/min for 30min to obtain emulsion D;

the preparation steps (3) and (4) of this example were the same as the steps (3) and (4) of example 4.

(5) Coating the white emulsion E obtained in the step (4) on the surface of the mask layer, controlling the thickness of the emulsion E layer to be 0.2mm, and drying at room temperature to obtain a transparent temperature-adjustable ventilation layer which is attached to the surface of the mask layer and is composed of a butyl acrylate-styrene copolymer composite negative heat material;

(6) adding 2 parts by weight of styrene into a container to obtain a solution F; dissolving 0.5 part by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain solution G;

the preparation steps (7) and (8) of this example were the same as the steps (7) and (8) of example 4.

(9) And (3) coating the white emulsion I obtained in the step (8) on the surface of the ventilation layer obtained in the step (5), controlling the thickness of the emulsion I layer to be 0.1mm, and drying at room temperature to obtain a hydrophilic layer which is attached to the surface of the ventilation layer and consists of hydroxypropyl acrylate-styrene-polyvinyl alcohol copolymer.

Comparative example 12

In this example, a mulching film was prepared according to document 4, in which the intermediate layer also contained a negative thermal material, but the negative thermal material was ZrW ₂ O ₈ Instead of ZrW loaded with benzoyl peroxide ₂ O ₈ And the upper and lower two layers are both polyethylene films, the preparation steps of the mulching film of the embodiment are as follows:

(1) firstly, dissolving 1 part by weight of liquid rubber in 3 parts by weight of toluene solvent, adding 1 part by weight of black humic acid powder into the solution after the liquid rubber is completely dissolved, stirring at room temperature for 10 hours at the stirring speed of 250r/min, and obtaining black liquid rubber composite humic acid glue solution after the stirring is finished;

(2) ZrW with 65-80 meshes of particles is added into the liquid rubber composite humic acid glue solution obtained in the step 1 ₂ O ₈ Particles of a negative thermal material of which ZrW ₂ O ₈ The weight ratio of the particles to the liquid natural rubber composite humic acid glue solution is 1: 26.8 (excluding solvent in glue solution, the weight ratio is the same as that of the negative heat material in the copolymer of the ventilation layer in the example 4), then stirring for 10 hours at room temperature, the stirring speed is 250r/min, and ZrW is obtained after the stirring is finished ₂ O ₈ Liquid rubber composite humic acid glue solution of negative heat material particles;

(3) ZrW contained in the ZrW component obtained in the step (2) ₂ O ₈ The liquid rubber composite humic acid glue solution of the negative heat material particles is coated on a layer of glue solution with air holes (the aperture is 1.1mm, and the distribution density of the air holes is 9/m) ² Same as example 4), ZrW was controlled to be contained in the polyethylene film ₂ O ₈ The thickness of the liquid natural rubber composite humic acid glue solution of the negative thermal material particles is 0.2mm (same as the thickness of the middle layer in the example 4), and then the liquid natural rubber composite humic acid glue solution contains ZrW ₂ O ₈ A layer of air holes (the aperture is 1.1mm, and the distribution density of the air holes is 9/m) is laid above the liquid natural rubber composite humic acid glue layer of the negative heat material particles ² ) The polyethylene film of (3) to obtain a three-layer composite film, i.e. the upper layer and the lower layer are both polyethylene films with air holes, and the middle layer is a film containing ZrW ₂ O ₈ A liquid rubber composite humic acid gum liquid layer of negative heat material particles;

(4) and (4) air-drying the composite film obtained in the step (3) at 50-70 ℃ to volatilize the organic solvent in the glue solution of the middle layer of the composite film from the air holes on the upper and lower layers of polyethylene films, and finally obtaining the black mulching film.

Application example 13

In this example, the soil surface is covered with the mulching films obtained in example 1, example 4, example 5 and comparative examples 6 to 12, and the specific test steps are as follows:

(1) selecting a vegetable planting field, wherein the places are east longitude: 118.97539027571867 ° and north latitude: 32.066403113172214 deg. planting garland chrysanthemum in the field;

(2) applying urea fertilizer to the field in 2018, 11/2 days, wherein the urea application amount is 25g/m ² Dividing the field into 10 fields with the size of 0.5m multiplied by 0.5m, and dividing the field into 0.1m intervals;

(3) the mulching films prepared in the examples 1, 4, 5 and 6-12 are cut out to be 0.8m multiplied by 0.8m in size and are respectively laid on the 10 fields, the height of the mulching film from the ground is about 10cm, the edge of each mulching film is embedded into the ground 5cm at the edge of each field and is pressed by soil blocks, and the space surrounded by the mulching films is a closed space.

Effects of the embodiment

This example was conducted to perform the following performance tests on each of the mulching films of application example 13 (including the mulching films obtained in example 1, example 4, example 5, and comparative examples 6 to 12).

1. Soil temperature test for mulching

A GPRS type soil temperature and humidity sensor (model: JXBS-7001-TR, supplier: electronics technology limited company for smooth communication, the sensor is used for transmitting soil temperature and humidity data by depending on a mobile phone signal network) is adopted to automatically measure and upload the average temperature of the soil depth covered by the film at a position of 5 cm. The measurement period is 3 consecutive days in 11 months and 5-7 days in 2018, and the measurement time is 12 days per day: 00 o and night 2: and 00, the average temperature of the soil is (the sum of the soil temperatures at a certain time point of 3 days)/3.

2. And (5) testing the air exchange performance of the mulching film.

(1)CO ₂ Gas testing

A GPRS type carbon dioxide sensor (model: JXBS-7001-CO2, supplier: Jing Xue Tong electronic technology Co., Ltd.) is adopted to carry out CO in gas by means of a mobile phone signal network ₂ Concentration data transmission) automatic measurement and upload of CO in the plastic mulching space ₂ The average concentration of the gas. The measurement period is 3 consecutive days in 11 months and 5-7 days in 2018, and the measurement time is 12 days per day: 00 o and night 2: 00 o point, CO ₂ Average concentration (3 days certain time point CO) ₂ The sum of the concentrations)/3.

(2)NH ₃ Gas concentration measurement

Adopts a GPRS type ammonia gas sensor (model: JXBS-7001-NH3, supplier: Jing Xue Tong electronic technology Limited company, the sensor depends on a mobile phone signal network to transmit ammonia gas concentration data in gas) to automatically measure and upload NH in the plastic film covered space ₃ The average concentration of the gas. The measurement period is 3 consecutive days in 11 months and 5-7 days in 2018, and the measurement time is 12 days per day: 00 o and night 2: 00 point, NH ₃ Mean concentration (3 days certain time point NH) ₃ The sum of the concentrations)/3.

3. Water drop test of mulch film

Selecting a mulching film with an area of 0.1m multiplied by 0.1m, and counting the average number of water drops with the inner diameter of more than 2mm in the area. Document 4 (Zhang Shengjun et al, research on the burning of drip irrigation tapes by condensed water drops under mulch [ J ], water-saving irrigation, 2014, 6, 29-31) describes that when the diameter of the water drops of the mulch film is larger than a certain value (for example, 5mm), the lens formed by the water drops can focus sunlight and can obviously burn to crops covered by the mulch film, so that the smaller the number of the water drops on the mulch film is, the more beneficial the agricultural production is. The measurement period is 3 consecutive days in 11 months and 5-7 days in 2018, and the measurement time is 12 days per day: and 00 points, wherein the average number of the water drops is (sum of the number of the water drops in 3 days)/3.

4. Contact angle test of mulching film on surface facing soil

Connecting a power supply of a DSA100 optical contact angle measuring instrument, cutting 3 film samples with the same size from the obtained mulching film of each embodiment, fixing the 3 film samples on a workbench with the soil surface facing upwards, forming 0.01ml of distilled water on a needle head into water drops, dropping the water drops on the surface of the film samples, standing the water drops on the film samples for 50s, rotating a cross line in an eyepiece to make a tangent line at the contact point of the water drops and the film samples, and determining the included angle between the tangent line and the horizontal plane of the film samples as a contact angle. The contact angles were measured at 3 different locations and the average was taken as the contact angle of the soil-facing side of this film sample.

5. As can be seen from the results in tables 1-4, the soil covered with the films of examples 1, 4 and 5 can maintain the soil temperature at 15.9-16.1 ℃ at 12 days, which is similar to the ambient temperature during the day; the temperature of the soil at 2 o' clock night can be maintained at 15.4-15.7 deg.C, which can be about 8.6 deg.C higher than the ambient temperature. The reason is that the mulching film exchange pores are opened in daytime, hot air in the external environment enters the mulching film space in daytime, the hot air can heat the soil covered by the mulching film to reach a similar degree with the ambient temperature, the ventilation pores of the mulching films of the embodiments 1, 4 and 5 are closed at night, and cold air cannot enter the mulching film covered space at night, so that the temperature of the soil covered by the mulching film is not reduced too fast, and the temperature of the soil covered by the mulching films of the embodiments 1, 4 and 5 at night can be far higher than the external ambient temperature. The reason why the carbon dioxide concentration range of the plastic film covered space in examples 1, 4 and 5 is 381ppm for 370 during day 12, 1000ppm for 968 during night 2 is that the carbon dioxide concentration in the plastic film covered space is greater than that during day is that the crops mainly absorb carbon dioxide due to photosynthesis under the action of sunlight during day, the crops mainly absorb carbon dioxide due to respiration during night, and a large amount of carbon dioxide is exhaled during night. The mulching spaces of examples 1, 4 and 5 had carbon dioxide concentrations higher than 300ppm required for photosynthesis although the carbon dioxide concentrations became low during the day, which was sufficient to maintain normal photosynthesis of crops. This is because the ventilating holes of the mulching films of examples 1, 4 and 5 are opened in the daytime, and carbon dioxide in the external atmosphere can be supplemented into the space for mulching films, so that the concentration of carbon dioxide in the space for mulching films is not too low. The concentration range of ammonia gas in the plastic film covered space of the embodiments 1, 4 and 5 is 0.7-0.9ppm at 12 o' clock in the daytime, and the concentration range of ammonia gas in the night is 0.9-1.2ppm, and the ammonia gas range is far lower than 5ppm, so that the growth of crops is not damaged, because the ventilation holes of the plastic films of the embodiments 1, 4 and 5 can be opened in the daytime, harmful ammonia gas can be released to the external environment in time, and the harmful ammonia gas cannot be accumulated in the plastic film covered space continuously. The contact angles of the hydrophilic layers of the mulching films of examples 1, 4 and 5 are less than 10 degrees, which shows that the hydrophilic layers of the mulching films of examples 1, 4 and 5 have excellent hydrophilicity, water drops spread on the hydrophilic layers and can not be formed into water drops, and the results in Table 4 show that no obvious water drops are found on the surfaces of the mulching films of examples 1, 4 and 5, and the hydrophilic layers of the mulching films of the above examples have the effect of not forming water drops. The above results show that the mulching film prepared by the composition range and the preparation method of the invention claims can effectively maintain the temperature of soil, effectively increase the concentration of carbon dioxide in the space covered by the mulching film, reduce the concentration of harmful ammonia gas and simultaneously have no obvious water drops on the mulching film.

For comparative example 6, the results in Table 2 show that the carbon dioxide concentration in the space covered by the mulch film prepared in comparative example 6 was 100ppm at 12 o' clock in the day, which is much less than 300ppm required for crop photosynthesis; in addition, the ammonia concentration in the space covered by the mulching film prepared in the comparative example 6 is 46-5.2ppm which is 5.1-7.4 times of the ammonia concentration in the space covered by the mulching film prepared in the example 4. The difference between the comparative example 6 and the example 4 is that the temperature-adjustable air exchange layer is not provided with negative thermal materials, so that the mulching film prepared by the comparative example 6 has no performance of air exchange along with temperature change, which can lead the mulching film of the comparative example 6 not to be capable of supplementing carbon dioxide from outside fresh air into the mulching film space in time and not to be capable of exhausting harmful ammonia gas in the mulching film space of the comparative example 6 in time.

For comparative example 7, the results in Table 2 show that the concentration of carbon dioxide in the space covered by the mulching film prepared in comparative example 7 is 210ppm at 12 o' clock in the day, which is far lower than the concentration of 300ppm required for photosynthesis of crops; in addition, the concentration of ammonia gas in the space covered with the mulching film prepared in comparative example 7 was 4.1 to 4.2ppm, which was 4.6 to 6 times the concentration of ammonia gas in the space covered with the mulching film of example 4. Comparative example 7 differs from example 4 in that the negative thermal material in the temperature adjustable gas exchange layer is ZrW ₂ O ₈ Instead of ZrW loaded with benzoyl peroxide ₂ O ₈ ZrW without benzoyl peroxide loading ₂ O ₈ The negative thermal material cannot initiate the polymerization of organic monomers around the particles of the negative thermal material on the surfaces of the particles, and a dense and rigid polymer shell cannot be formed on the surfaces of the particles of the negative thermal material, which causes ZrW to form when the temperature is increased ₂ O ₈ Temperature of the granulesIncrease in degree and contract, but ZrW ₂ O ₈ The polymer matrix with weak rigidity around the particles shrinks and deforms, so that effective holes are not formed between the negative heat material and the polymer shell, and therefore, the mulching film of the comparison implementation 7 has no effective ventilation effect, so that the mulching film of the comparison implementation 7 cannot timely supplement carbon dioxide in external fresh air into the mulching film covering space, and ammonia gas in the mulching film covering space cannot be timely discharged.

For comparative example 8, the results in table 1 show that the soil covered by the mulch film prepared in comparative example 8 has a temperature of 10.1 ℃ at 2 o' clock night, which is 5.6 ℃ lower than that of example 4, i.e., the mulch film of comparative example 8 does not effectively maintain soil temperature at night. This is because the difference between the comparative example 8 and the example 4 is that the particle size of the negative thermal material in the temperature-adjustable ventilation layer is 9-28 mesh, i.e. the particle size of the negative thermal material is larger than the range stated in the claims, which makes the particle size of the negative thermal material far exceed the sum of the thicknesses of the ventilation layer and the hydrophilic layer, i.e. part of the negative thermal material particles not only penetrate through the ventilation layer and the hydrophilic layer, but also protrude from the surface of the hydrophilic layer to a significant extent, which results in that the polymer matrix or shell is difficult to form effective coating of the negative thermal material, i.e. larger gap defects are always generated between the negative thermal material particles and the polymer matrix, so that cold air enters the space covered by the mulching film through the larger gaps at night, thereby reducing the temperature of the soil covered by the mulching film too fast at night.

For comparative example 9, the results in Table 2 show that the carbon dioxide concentration in the space covered by the mulch of comparative example 9 was 180ppm at 12 o' clock in the day, which is much less than 300ppm required for crop photosynthesis; in addition, the ammonia concentration in the space covered by the mulching film prepared in the comparative example 9 also reaches 4.0-4.1ppm, which is 4.6-5.8 times of the ammonia concentration in the space covered by the mulching film prepared in the example 4. This is because the difference between comparative example 9 and example 4 is that the particle size of the negative thermal material in the temperature-adjustable gas exchange layer is 115-400 mesh, which is lower than the range stated in the claims, which results in that the particles of the negative thermal material are buried too deeply in the gas exchange layer and the hydrophilic layer, the gap between the negative thermal material and the polymer matrix is also buried deeply in the polymer matrix, and the surface of the gas exchange layer and the hydrophilic layer has no significant pores, which makes it difficult to achieve effective exchange of gas inside and outside the membrane.

For comparative example 10, the results in table 4 show that the number of the beads on the mulching film prepared in comparative example 10 reaches 40, the contact angle of the hydrophilic layer is 113 degrees, which is much higher than the contact angles of the beads on the mulching film prepared in example 4, which are 0 and 4 degrees. This is because the difference between comparative example 10 and example 4 is that the use of hydroxypropyl acrylate in the gas exchange layer in an amount of 10 parts by weight and polyvinyl alcohol in an amount of 15 parts by weight, both of which are used in amounts below the ranges recited in the claims, results in too little hydrophilic component in the hydrophilic layer, making it difficult for the hydrophilic layer of comparative example 10 to spread out and bind more water droplets. The soil temperature (13.4 ℃ at 12 days and 11.1 ℃ at 2 nights) of the mulching film of the comparative example 10 is also far lower than that of the mulching film of the example 4 because more water drops on the mulching film of the comparative example 10 can prevent sunlight from entering the space of the mulching film and more sunlight energy is absorbed by the evaporation of the water drops.

For comparative example 11, the results in Table 1 show that the soil covered with the film of comparative example 11 has a temperature of 12 ℃ at 12 o 'clock in the day and 9.6 ℃ at 2 o' clock in the night, which are much lower than the soil covered with the film of example 4. The results in table 4 show that the number of beads on the membrane of comparative example 11 reaches 29, the contact angle of the hydrophilic layer is 86 degrees, which is much higher than the contact angle of 0 beads on the membrane of example 4 and 4 degrees of the hydrophilic layer. This is because the mulching film of comparative example 11 is different from the mulching film of example 4 in that chlorosulfonated polyethylene, which has excellent adhesiveness and allows effective compatibility and adhesion between coatings, is not used in both the air exchange layer and the hydrophilic layer, and comparative example 11 does not use chlorosulfonated polyethylene, which results in poor adhesion of the air exchange layer to the mulching film layer and large pores between the air exchange layer and the mulching film layer, which allows cold air outside the mulching film at night to easily enter the space of the mulching film through the pores, thereby reducing the soil temperature too quickly. In addition, the hydrophilic layer of comparative example 11 also did not use chlorosulfonated polyethylene, so that the adhesion of the hydrophilic layer on the surface of the ventilation layer was not good, and a part of the hydrophilic layer was peeled off, and the hydrophilicity of the hydrophilic layer was lowered, so that the mulching film of comparative example 11 had more water drops.

For comparative example 12, the results in Table 1 show that the temperature of the soil covered by the mulch film prepared in comparative example 12 was 11.9 ℃ at 12 o 'clock day and 9.8 ℃ at 2 o' clock night, which are much lower than the temperature of the soil covered by the mulch film of example 4. This is because the mulching film prepared in comparative example 12 is black and opaque, sunlight does not easily penetrate through the mulching film to heat the space covered by the mulching film and the soil, resulting in a slow temperature rise of the soil, particularly in winter, when sunlight is most sufficient during one day at 12 o' clock, but comparative example 12 cannot effectively use the sunlight energy during this period of time to rapidly raise the temperature of the soil, and also because the soil cannot absorb and store enough heat during the day when sunlight is most sufficient, the temperature of the soil covered by the mulching film of comparative example 12 is also low during night. The results in Table 2 show that the carbon dioxide concentration in the space covered by the mulching film of comparative example 12 is 230ppm at 12 o' clock in the day, which is much lower than the concentration of 300ppm required for photosynthesis of crops; in addition, the concentration of ammonia in the space covered by the mulching film of comparative example 12 is 5.1ppm, which is much higher than that in the space covered by the mulching film of example 4. This is probably because the butyl acrylate and styrene monomer as in example 4 are not used in the intermediate layer of comparative example 12, and the negative thermal material loaded with the initiator is not used, which results in that a compact and rigid polymer shell is not formed on the surface of the negative thermal material particles, and further, when the negative thermal material particles expand or contract, the polymer matrix around the negative thermal material particles expands or contracts due to too large elasticity, so that the pores between the negative thermal material particles and the polymer matrix may be too small, which results in that the film of comparative example 12 loses the temperature regulation pore size and ventilation effect to some extent, and finally, CO in the outside fresh air is caused ₂ It was difficult to supplement NH in the space covered with the mulching film of comparative example 12, and the space covered with the mulching film of comparative example 12 ₃ Difficult to be exchanged outside the mulching film in time. Table 4 shows the results of comparative example 12 on the mulching filmThe number of the water drops reaches 62, and the contact angle of the water drops towards the soil surface is 121 degrees, which is much higher than the contact angle of 0 water drops and the hydrophilic layer of the mulching film prepared in example 4 by 4 degrees. This is because the upper and lower layers of the mulching film of comparative example 12 are made of hydrophobic polymer material of polyethylene, and the mulching film made of this material is prone to generate water drops, which prevent sunlight from directly entering the space covered by the mulching film, and at the same time, the water drops are evaporated and absorb a large amount of heat energy, which is also an important factor that causes the temperature of the soil covered by the mulching film of comparative example 12 to be lower.

Table 1 average temperature of soil covered with the mulching films obtained in examples 1, 4, 5, and comparative examples 6 to 12 at a position of 5cm depth, 12: the average ambient temperature at point 00 is 16.4 ℃, and the night outside the mulching film is 2: the average ambient temperature at point 00 was 6.8 deg.C

Table 2 CO in the space covered with the mulching films obtained in example 1, example 4, example 5, and comparative examples 6 to 12 ₂ Average concentration of gas, CO in the environment outside the mulch ₂ The average concentration of the gas was 400ppm

Table 3 NH in the space covered with the mulching films obtained in examples 1, 4, 5, and comparative examples 6 to 12 ₃ Average concentration of gas, NH in the environment outside the mulch ₃ The average concentration of gas was 0ppm

TABLE 4 average number of water drops formed in the area of 0.1 m.times.0.1 m and contact angle of the water drops to the soil surface of the mulching films obtained in example 1, example 4, example 5 and comparative examples 6 to 12

Claims

1. The utility model provides a ventilative anhydrous drip plastic film based on but temperature regulation layer of taking a breath, a serial communication port, the plastic film from top to bottom sets gradually facial mask layer (1), but temperature regulation's layer of taking a breath (2) and hydrophilic layer (3), facial mask layer distribute bleeder vent (11), but temperature regulation's layer of taking a breath by compound negative heat material of butyl acrylate-styrene-chlorosulfonated polyethylene copolymer constitute, negative heat material (21) are ZrW of load benzoyl peroxide ₂ O ₈ The butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material comprises the following components in parts by weight: 24-35 parts of butyl acrylate, 3-7 parts of styrene, 2.5-6.5 parts of chlorosulfonated polyethylene and 3-6 parts of negative heat material, wherein the hydrophilic layer is composed of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer, and the hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer comprises the following components in parts by weight: 15-30 parts of hydroxypropyl acrylate, 1-5 parts of styrene, 1-5 parts of chlorosulfonated polyethylene and 20-40 parts of polyvinyl alcohol; a preparation method of the breathable water-drop-free mulching film based on the temperature-adjustable air exchange layer comprises the following steps:

(1) dissolving 1 part by weight of benzoyl peroxide in 99 parts by weight of toluene solvent to obtain solution A, and then dissolving 30 parts by weight of ZrW with particle size of 100-32 meshes ₂ O ₈ Soaking in the A solution at 25 deg.C for 15h, and soaking ZrW ₂ O ₈ Taking out, and air-drying at room temperature for 10h to obtain the ZrW loaded with benzoyl peroxide ₂ O ₈ Negative thermal material, wherein the weight of benzoyl peroxide is in the loadZrW of benzoyl peroxide ₂ O ₈ 0.1-0.12% of the total weight of the negative thermal material;

(2) dissolving 2.5-6.5 parts by weight of chlorosulfonated polyethylene in 3-7 parts by weight of styrene in a container to obtain a solution B; dissolving 0.5 part by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain a solution C; then adding sodium dodecyl sulfate, OP-10 emulsifier and deionized water into the solution B, and stirring for 30min at room temperature at the rotation speed of 350-;

(3) heating a container containing the emulsion D in a water bath to a certain temperature, and then obtaining the benzoyl peroxide-loaded ZrW from the solution obtained in the step (1) ₂ O ₈ Taking out 3-6 parts by weight of the negative heat material particles, adding the negative heat material particles into the emulsion D, and dripping 24-35 parts by weight of butyl acrylate into the emulsion D under stirring at the dripping speed of 1 drop per 2 seconds and the stirring speed of 250 r/min; dropwise adding the solution C obtained in the step (2) into the emulsion D at the dropping speed of 1 drop per 5 seconds while dropwise adding butyl acrylate;

(4) after the butyl acrylate and the solution C are dropwise added in the step (3), heating the reaction system to a certain temperature, and stirring at a constant stirring speed for reaction for a certain time; after the constant-temperature stirring reaction is finished, cooling the obtained mixed solution to room temperature, and adding concentrated ammonia water to adjust the pH of the mixed solution to be neutral to obtain white emulsion E;

(5) the temperature-adjustable ventilation layer based on the steps (1) to (4) is prepared by the following preparation method: coating the white emulsion E obtained in the step (4) on the surface of the facial mask layer, controlling the thickness of the emulsion E layer to be 0.1-0.3mm, and drying at room temperature to obtain a transparent temperature-adjustable ventilation layer which is attached to the surface of the facial mask layer and consists of a butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material;

(6) dissolving 1-5 parts by weight of chlorosulfonated polyethylene in 1-5 parts by weight of styrene to obtain a solution F; dissolving 0.5 part by weight of ammonium persulfate initiator in 20 parts by weight of deionized water to obtain a solution G;

(8) heating a container containing the emulsion H obtained in the step (7) in water bath to 82 ℃, and then adding 15-30 parts by weight of hydroxypropyl acrylate into the emulsion H under stirring at the temperature, wherein the dropping speed is 1 drop per 2 seconds, and the stirring speed is 250 r/min; dripping the solution G obtained in the step (6) into the emulsion H at the dripping speed of 1 drop per 5 seconds while dripping hydroxypropyl acrylate; after the hydroxypropyl acrylate and the solution G are dripped, heating the reaction system to 85 ℃, and stirring and reacting for 5 hours at constant temperature at the temperature, wherein the stirring speed is 250 r/min; after the constant-temperature stirring reaction is finished, cooling the obtained mixed solution to room temperature, and adding concentrated ammonia water to adjust the pH of the mixed solution to be neutral to obtain white emulsion I;

(9) coating the white emulsion I obtained in the step (8) on the surface of the ventilation layer which is obtained in the step (5) and can be adjusted in temperature, controlling the thickness of the emulsion I layer to be 0.08-0.2mm, and drying at room temperature to obtain a hydrophilic layer which is attached to the surface of the ventilation layer and consists of hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer;

the breathable water-drop-free mulching film based on the temperature-adjustable air exchange layer can be obtained through the steps (1) - (9).

2. The method according to claim 1, wherein the mask layer is made of polyethylene or polyvinyl chloride, the size of the pores of the mask layer with the air holes is 0.5-3mm, and the distribution density of the air holes is 5-20/m ² 。

3. The preparation method of claim 1, wherein the butyl acrylate-styrene-chlorosulfonated polyethylene copolymer composite negative heat material comprises the following components in parts by weight: 32 parts of butyl acrylate, 6 parts of styrene, 5 parts of chlorosulfonated polyethylene and 4 parts of negative heat material.

4. The preparation method of claim 1, wherein the hydroxypropyl acrylate-styrene-chlorosulfonated polyethylene-polyvinyl alcohol copolymer comprises the following components in parts by weight: 19 parts of hydroxypropyl acrylate, 2 parts of styrene, 2 parts of chlorosulfonated polyethylene and 25 parts of polyvinyl alcohol.

5. The method according to claim 1, wherein the sodium dodecylsulfate in the step (2) is 2.3 parts by weight, the OP-10 emulsifier is 3.1 parts by weight, and the deionized water is 20 parts by weight.

6. The method according to claim 1, wherein the temperature to which the container for preparing the emulsion D in the step (3) is heated in the water bath is 82 ℃.

7. The production method according to claim 1, wherein the temperature to which the reaction system is warmed up to 85 ℃ after the addition of the butyl acrylate and the solution C in the step (3) is completed as described in the production step (4).

8. The preparation method according to claim 1, characterized in that the isothermal stirring reaction time in the preparation step (4) is 5h, and the stirring speed is 250 r/min.